Localized panel stiffener

ABSTRACT

A device (10) comprising a carrier material (14) and a matrix material (12) deposited onto the carrier material in a pattern that leaves a predetermined amount of space (18) between each deposition of matrix material.

TECHNICAL FIELD

The present teachings relate generally to a reinforcement member thatincludes a matrix material and a carrier material.

BACKGROUND

The automotive industry is emphasizing efforts to reduce overall vehicleweight in order to obtain improved fuel efficiency. One common way toreduce vehicle weight is to reduce the thickness of the sheet metal.Frequently, the areas of the vehicle that form vehicle closures will bemade with a thinner gauge metal. These vehicle closures include doors,trunks, hoods and liftgates. One area of particular interest is withvehicle doors. The thickness of the metal used for doors is sufficientlythin such that it is highly susceptible to buckling from even thesmallest amounts of pressure. To prevent such buckling, localizedstiffness in selected areas of the door is increased by the use ofthermosetting panel stiffeners. These panel stiffeners are typicallyglass reinforced with an epoxy matrix. However, as the gauge of metalcontinues to thin, these typical panel stiffeners are causing the thinmetal to deform (commonly referred to as read-through). Therefore thereis a need for an improved panel stiffener that provides stiffness tothin sheet metal yet does not result in deformation of the metal.

SUMMARY OF THE INVENTION

In a first aspect the present teachings contemplate a device comprisinga carrier material and a matrix material deposited onto the carriermaterial in a pattern that leaves a predetermined amount of spacebetween each deposition of matrix material.

Each deposition of matrix material may be at least about 0.5 mm indiameter and less than about 10 mm in diameter. The device may beflexible (e.g., capable of easily bending without breaking). The devicemay bend under its own weight when held at its end. The matrix materialmay be an activatable material and the volumetric activation of thematrix material is at least about 100% and less than about 300%. Thematrix material may include a structural adhesive material. The matrixmaterial may include a sealant material. Each deposition of matrixmaterial may be at least about 1 mm in diameter and less than about 4 mmin diameter. The carrier may be free of any sharp corners and includesonly rounded corners. The predetermined amount of space between eachdeposition of matrix material may be at least about 0.5 mm, at leastabout 1 mm, at least about 2 mm or even at least about 5 mm. The devicemay include an elastic material deposited onto the carrier material in apattern that leaves a predetermined amount of space between eachdeposition of elastic material. The matrix material and the elasticmaterial may be deposited in an alternating pattern onto the carrier.

The teachings herein further provide for a device comprising a carriermaterial and a matrix material deposited onto the carrier material andintended for direct contact with a sheet metal surface, wherein thecoefficient of thermal expansion of the matrix material is substantiallythe same as the coefficient of thermal expansion of the sheet metal.

The sheet metal may be steel. The coefficient of thermal expansion maybe at least about 5×10⁻⁶ m/mK. The coefficient of thermal expansion maybe at least about 10×10⁻⁶ m/mK.

The teachings herein contemplate a device for the structuralreinforcement of body stampings with a matrix material and associatedcarrier, whereby the matrix material is deposited in a pattern withspaces in between the depositions of matrix material. The devicedisclosed herein may allow for effective reinforcing of a panel whileproducing substantially no deformation of the panel.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top-down view of an illustrative example of a device inaccordance with the present teachings.

FIG. 2 shows a top-down view of an illustrative example of a device inaccordance with the present teachings.

FIG. 3 shows a top-down view of an illustrative example of a device inaccordance with the present teachings.

FIG. 4 shows a top-down view of an illustrative example of a device inaccordance with the present teachings.

FIG. 5 shows a top-down view of an illustrative example of a device inaccordance with the present teachings.

DETAILED DESCRIPTION

The explanations and illustrations presented herein are intended toacquaint others skilled in the art with the teachings, its principles,and its practical application. Those skilled in the art may adapt andapply the teachings in its numerous forms, as may be best suited to therequirements of a particular use. Accordingly, the specific embodimentsof the present teachings as set forth are not intended as beingexhaustive or limiting of the teachings. The scope of the teachingsshould, therefore, be determined not with reference to the abovedescription, but should instead be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. The disclosures of all articles and references,including patent applications and publications, are incorporated byreference for all purposes. Other combinations are also possible as willbe gleaned from the following claims, which are also hereby incorporatedby reference into this written description.

This application claims the benefit of the filing date of U.S.Provisional Application No. 62/161,523, filed May 14, 2015; and U.S.Provisional Application No. 62/164,224, filed May 20, 2015, the contentsof these applications being hereby incorporated by reference for allpurposes.

The devices described herein include a carrier and a matrix materialdeposited thereon. The nature of both the carrier and the matrixmaterial are such that they can be easily applied to a very thin gaugemetal part while avoiding read-through on the surface (e.g., a class-Asurface) of the metal part. The spaces in between the depositions ofmatrix material are integral to avoiding read-through, in that if thematrix material were to be applied as a full sheet onto a thin gaugemetal part (e.g., in a constant sheet with no spaces in between) theactivation of the matrix material would likely result in read-through.

The matrix material may be located onto only one surface of the carrier.The device may thus be incapable of bonding two surfaces together. Thedevice may be formed as a patch for providing localized stiffness to ametallic panel.

The matrix material may be located onto the carrier in any shape orpattern such that predetermined spaces exist between each deposition ofmatrix material. The matrix material may be deposited in plots, whichmay have rounded edges. The sizes of the plots may be consistent or mayvary along the carrier. The matrix material may be deposited in strips,where the distance between each strip may be consistent oalong thecarrier. Alternatively, the distance between each strip may be varyalong the carrier. The strips may all be deposited in one direction suchthat the strips run parallel to one another. The strips may be depositedsuch that a first strip may be located in a skew or even a perpendicularrelationship with a second strip. The carrier may include a singledeposition of matrix material or a plurality of depositions of matrixmaterial.

The matrix material of the present invention may be an epoxy-basedmaterial and may be activatable to form an epoxy-based adhesive materialupon activation. The matrix material may be at least partially tacky atroom temperature (e.g., about 23° C.) and may also be tacky attemperatures between about 0° C. and about 80° C. The matrix materialmay alternatively be dry to the touch at room temperature. Additionally,the matrix material preferably exhibits reinforcement characteristics(e.g., imparts rigidity, stiffness, strength or a combination thereof toa member upon which it is located). It is also preferable for the matrixmaterial to be activated (by heat, UV light, induction heating, or thelike) to expand or otherwise activate and wet surfaces which the matrixmaterial contacts. After activation (which may or may not includeexpansion), the matrix material preferably cures, hardens and adheres tothe surfaces that it contacts. For application purposes, it is oftenpreferable that the matrix material exhibit flexibility, particularlywhen the matrix material is to be applied to a contoured surface of avehicle body. Once applied, however, it is typically preferable for thematrix material to be activatable to soften, expand (e.g., foam), cure,harden or a combination thereof. For example, and without limitation, atypical matrix material will include a polymeric material, such as anepoxy resin or ethylene-based polymer which, when compounded withappropriate ingredients (typically a blowing and curing agent), expandsand cures in a reliable and predicable manner upon the application ofheat or the occurrence of a particular ambient condition. From achemical standpoint for a thermally-activated material, the matrixmaterial may be initially processed as a flowable material beforecuring. Thereafter, the material preferably cross-links upon curing,which makes the material substantially incapable of further flow.

The epoxy may be aliphatic, cycloaliphatic, aromatic or the like. Theepoxy may be supplied as a solid (e.g., as pellets, chunks, pieces orthe like) or a liquid. The epoxy may include an ethylene copolymer orterpolymer that may possess an alpha-olefin. As a copolymer orterpolymer, the polymer is composed of two or three different monomers,i.e., small molecules with high chemical reactivity that are capable oflinking up with similar molecules. One exemplary epoxy resin may be aphenolic resin, which may be a novalac type or other type resin. Otherpreferred epoxy containing materials may include a bisphenol-Aepichlorohydrin ether polymer, or a bisphenol-A epoxy resin which may bemodified with butadiene or another polymeric additive. Examples ofsuitable epoxy-based materials, which may be used as in the matrixmaterial are sold under the product designations L5020, L5010, L5224,L8000, L5001 and are commercially available from L&L Products, Romeo,Mich. According to preferred formulations, the base material can includeup to about 50% by weight epoxy resins, more preferably, up to about 65%by weight epoxy resins, and even more preferably up to about 80% byweight epoxy resins.

Advantageously, the matrix material of the present invention may beformed or otherwise processed in a variety of ways. For example,preferred matrix materials can be processed by injection molding,extrusion, compression molding or with a robotically controlled extrudersuch as a mini-applicator. A controlled extruder may allow for preciseplacement of one or more of the matrix material and elastic material.

The elastic material may be a material that provides vibration dampingto the sheet metal. The elastic material may also be an activatable andmay be capable of expansion, similar to the matrix material.

The matrix material and/or the elastic material may be formulated tohave a desired coefficient of thermal expansion. This coefficient ofthermal expansion may be selected so that it is similar to that of ametal to which the matrix material will be applied during use of thedevice. A filler material may be specifically selected to assist inmatching the coefficient of thermal expansion of the matrix material tothat of the sheet metal.

The carrier material for receiving the matrix material may be a glassmaterial (e.g., a fiberglass material), which may be a glass meshmaterial. The carrier may include non-conductive threads or wire (e.g.,elongated filament, fibrous, or fabric material), which may be appliedas a mat, a cloth, a roving, a netting, a mesh, a scrim, or the like. Insuch embodiments, the carrier material may be composed, for example, ofwoven or unwoven fibers, filaments or the like of cotton, glass (e.g.,E-glass or S-glass), fiberglass, Mylar, nylon, polyester, carbon,aramid, plastics, polymers (e.g., thermoplastics such as polyamides(e.g., nylon), PET (e.g., Mylar), polycarbonate, polyethylene,polypropylene, polybutylene (e.g., polybutylene terephthalate),polystyrene, polyurethane, vinyl, or any combination thereof, or othermaterials. As used herein, “threads,” or “wire” connotes a singlefilament of material, a braided bundle of filaments, or an unbraidedbundle of filaments. The carrier material may be aluminum. The carriermay comprise a metallic material. The carrier may be substantiallythicker than any film material. The carrier may be free of any filmmaterial. The carrier may be substantially rigid or may have a minimalamount of flexibility. The carrier may be less flexible than a filmmaterial.

In other applications, it may appreciable that the mesh material may bebead-like particles, aggregates, hollow material (e.g., hollowparticle), or otherwise, or any combination thereof. In suchembodiments, the strengthening material may be composed, for example, ofparticles or the like of glass (e.g., E-glass or S-glass), fiberglass,nylon, polyester, carbon, aramid, plastics, polymers (e.g.,thermoplastics such as polyamides (e.g., nylon), polycarbonate,polyethylene, polypropylene, polybutylene (e.g., polybutyleneterephthalate), polystyrene, polyurethane, vinyl, or any combinationthereof), or other materials.

FIG. 1 shows the device 10 having a matrix material 12. A carrier 14 islocated in planar contact with the matrix material layer 12. The carrier14 and matrix material 12 are formed having curved corners 16.

FIG. 2 shows the device 10 including a carrier 14 having a plurality ofportions of matrix material 12 deposited onto the carrier. A pluralityof spaces 18 are located in between the matrix material 12.

FIG. 3 shows the device 10 including a carrier 14 having a plurality ofportions of matrix material 12 deposited onto the carrier and also aplurality of portions of elastic material 20 deposited onto the carrier.A plurality of spaces 18 are located in between the matrix material 12and the elastic material 20.

FIG. 4 shows the device 10 including a carrier 14 having a plurality ofportions of matrix material 12 deposited onto the carrier. A pluralityof spaces 18 are located in between the matrix material 12.

FIG. 5 shows the device 10 including a carrier 14 having a plurality ofportions of matrix material 12 deposited in substantially straight linesonto the carrier. A plurality of spaces 18 are located in between thematrix material 12.

The devices disclosed herein provide added stiffness for thin gaugemetal panels without the issues related to read-through. Read-throughissues are substantially avoided by providing spaces in betweendepositions of activatable material. Issues are further avoided byproviding carriers with curved edges (e.g., carriers that aresubstantially free of any corners having right (or near right angles).The devices are preferably formed having matrix material on only onesurface of the carrier. The depositions of matrix material may besubstantially less than full coverage of a carrier.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time and the like is, for example, from 1 to 90,preferably from 20 to 80, more preferably from 30 to 70, it is intendedthat values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. areexpressly enumerated in this specification. For values which are lessthan one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate. These are only examples of what is specifically intendedand all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application in a similar manner. As can beseen, the teaching of amounts expressed as “parts by weight” herein alsocontemplates the same ranges expressed in terms of percent by weight.Thus, an expression in the Detailed Description of the Invention of arange in terms of at “‘x’ parts by weight of the resulting polymericblend composition” also contemplates a teaching of ranges of samerecited amount of “x” in percent by weight of the resulting polymericblend composition.”

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints. The use of “about” or “approximately” inconnection with a range applies to both ends of the range. Thus, “about20 to 30” is intended to cover “about 20 to about 30”, inclusive of atleast the specified endpoints.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. The term “consisting essentially of” to describe a combinationshall include the elements, ingredients, components or steps identified,and such other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination. The use of the terms “comprising” or “including” todescribe combinations of elements, ingredients, components or stepsherein also contemplates embodiments that consist essentially of theelements, ingredients, components or steps. By use of the term “may”herein, it is intended that any described attributes that “may” beincluded are optional.

Plural elements, ingredients, components or steps can be provided by asingle integrated element, ingredient, component or step. Alternatively,a single integrated element, ingredient, component or step might bedivided into separate plural elements, ingredients, components or steps.The disclosure of “a” or “one” to describe an element, ingredient,component or step is not intended to foreclose additional elements,ingredients, components or steps.

It is understood that the above description is intended to beillustrative and not restrictive. Many embodiments as well as manyapplications besides the examples provided will be apparent to those ofskill in the art upon reading the above description. The scope of theinvention should, therefore, be determined not with reference to theabove description, but should instead be determined with reference tothe appended claims, along with the full scope of equivalents to whichsuch claims are entitled. The disclosures of all articles andreferences, including patent applications and publications, areincorporated by reference for all purposes. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

1. A device comprising: a carrier material; and a matrix materialdeposited onto the carrier material in a pattern that leaves apredetermined amount of space between each deposition of matrixmaterial.
 2. The device of claim 1, wherein each deposition of matrixmaterial is about 0.5 mm or more in diameter and about 10 mm or less indiameter.
 3. The device of claim 1, wherein the device is capable ofbending without breaking.
 4. The device of claim 1, wherein the devicewill bend under its own weight when held at its end.
 5. The device ofclaim 1, wherein the matrix material is an activatable material and thevolumetric activation of the matrix material is at least about 100% andless than about 300%.
 6. The device of claim 1, wherein the matrixmaterial includes a structural adhesive material.
 7. The device of claim1, wherein the matrix material includes a sealant material.
 8. Thedevice of claim 1, wherein each deposition of matrix material is about 1mm or more in diameter and about 4 mm in diameter or less.
 9. The deviceof claim 1, wherein the carrier is free of any sharp corners andincludes only rounded corners.
 10. The device of claim 1, wherein thepredetermined amount of space between each deposition of matrix materialis at least about 0.5 mm, at least about 1 mm, at least about 2 mm oreven at least about 5 mm.
 11. The device of claim 1, including anelastic material deposited onto the carrier material in a pattern thatleaves a predetermined amount of space between each deposition ofelastic material.
 12. The device of claim 11, wherein the matrixmaterial and the elastic material are deposited in an alternatingpattern onto the carrier.
 13. The device of claim 1, wherein the matrixmaterial is deposited onto only one surface of the carrier.
 14. Thedevice of claim 1, wherein the carrier is substantially free of any filmmaterial.
 15. A device comprising: a carrier material; and a matrixmaterial deposited onto the carrier material and intended for directcontact with a sheet metal surface, wherein the coefficient of thermalexpansion of the matrix material is substantially the same as thecoefficient of thermal expansion of the sheet metal.
 16. The device ofclaim 15, wherein the sheet metal is steel.
 17. The device of claim 15,wherein the coefficient of thermal expansion is at least about 5×10⁻⁶m/mK.
 18. The device of claim 15, wherein the coefficient of thermalexpansion is at least about 10×10⁻⁶ m/mK.
 19. The device of claim 15,wherein the matrix material is deposited onto only one surface of thecarrier.
 20. The device of claim 15, wherein the carrier issubstantially free of any film material.